UV coordinates inaccurate, showing nearby pixels when not supposed to
This is not a bug, it is in the way UV-Mapping to a surface works. If the surfaces are at an angle, a certain amount of edge blending is going to occur. This can lead to unwanted seep-through of other parts of the texture.

It appears that the bleed in your texture is too small. Bleed is the amount of overfill that each island gets added on its edges. This in turn is causing the neighboring textures to show through. To get around this, you need to increase the spacing between the UV-islands.